This invention generally relates to golf balls, and specifically to golf balls comprising at least one interior layer comprising a plurality of protrusions. In this regard, the present invention concerns an improved process for producing a plurality of protrusions on the surface of an interior layer of a golf ball. Preferably, the plurality of protrusions extend outwardly from an outer surface of a core that is incorporated into a golf ball. The present invention is also directed to the resulting layers and finished golf balls produced utilizing such a process.
Traditionally, three types of golf balls are commercially available. The first type of ball available is a one-piece ball which is spherical and made essentially with the same material throughout the ball. The second type of ball available is a wound multi-layered ball having a core, an elastic thread wound about the core, and a cover. The third type of ball available is a non-wound multi-layered ball having at least one core layer and at least one cover layer.
With respect to wound and non-wound multi-layered golf balls, the outer and inner surfaces of the interim layers within the ball typically have a smooth, spherical configuration. Also, each layer of a golf ball typically has a different composition from that of an adjacent layer. Since the layers within a golf ball have different compositions and the various layers each have a spherical configuration, upon striking the ball with a club, the transfer of energy from the outer cover layer to the core is relatively poor. An inefficient transfer, i.e., loss of energy, results in less energy imparted to the ball and thus shorter distance and/or less desirable playing characteristics.
The present invention seeks to improve the transfer of energy in a wound or non-wound multi-layered golf ball by utilizing a new method of forming interior layers of a multi-layered golf ball.
The present subject matter is directed to a method of making a golf ball comprising the steps of forming a plurality of protrusion depressions on an inner surface of a mold; molding a center assembly having a plurality of outwardly extending protrusions from the mold; and molding a cover about the center assembly having the plurality of outwardly extending protrusions. The center assembly having a plurality of outwardly extending protrusions can be compression molded, injection-molded, reaction injection molded, or pin molded. Preferably, the plurality of protrusion profile depressions formed in the mold are hemispherical, angled, or stepped.
The present subject matter is also directed to a method of making a golf ball comprising the steps of molding a spherical center; machining a plurality of protrusion depressions on a mold; positioning the spherical center within the mold having the plurality of protrusion depressions; molding a mantle layer about the spherical center in the mold to form a center assembly having a plurality of outwardly extending protrusions; and molding a cover layer about the center assembly.
Additionally, the present subject matter is directed to a method of making a golf ball comprising the steps of forming a plurality of protrusion depressions on an inner surface of a mold; molding a center assembly having a plurality of outwardly extending protrusions from the mold; molding a mantle layer about the center assembly having the plurality of outwardly extending protrusions; and molding a cover about the mantle layer to thereby form a golf ball.
Also, the present subject matter is directed to a method of making a golf ball comprising the steps of molding a spherical center; forming a plurality of protrusion depressions on a mold adapted to receive a spherical center; positioning the spherical center within the mold having the plurality of protrusion depressions; molding a mantle layer about the spherical center in the mold having the plurality of protrusion depressions to form a center assembly having a plurality of outwardly extending protrusions; molding an intermediate layer about the center assembly having outwardly extending protrusions; and molding a cover about the intermediate layer to thereby obtain a golf ball.